E v aluatio n an d Tre at m e n t of Developmental Hip D y s p l a s i a in th e N e w b o r n and Infant Richard M. Schwend,
MD
a
, Brian A. Shaw,
MD
b,
*, Lee S. Segal,
MD
c
KEYWORDS Developmental hip dysplasia Acetabular dysplasia Hip subluxation Hip dislocation Ortolani maneuver Swaddling KEY POINTS Research over the past decade has reinforced most of the principles and recommendations of the 2000 American Academy of Pediatrics’ Clinical Practice Guideline: Early Detection of Developmental Dysplasia of the Hip. A reasonable goal for the primary care physician should be to prevent hip subluxation or dislocation by 6 months of age using the periodic examination. The Ortolani maneuver, in which a subluxated or dislocated femoral head is gently reduced into the acetabulum with hip abduction by the examiner, is the most important clinical test for detecting dysplasia in the newborn. Safe swaddling, in which the hips are not extended and does not restrict hip motion, does not increase the risk for developmental hip dysplasia. Despite best practice, young adults will still present with hip dysplasia that was not detected at birth.
Video of the Ortolani maneuver accompanies this article at http:// www.pediatric.theclinics.com/ INTRODUCTION
Developmental dysplasia of the hip (DDH) encompasses a spectrum of physical and imaging findings, ranging from mild temporary instability to frank dislocation. The Disclosure: none. a Orthopaedics and Pediatrics, UMKC, KUMC Director of Research Children’s Mercy Hospital, 2401 Gillham Road, Kansas City, MO 64108, USA; b Orthopaedic Surgery, University of Colorado School of Medicine, Children’s Hospital Colorado and Memorial Health System, Colorado Springs, 4125 Briargate Parkway, Suite 100, Colorado Springs, CO 80920, USA; C Department of Orthopaedics, University of Wisconsin Hospital and Clinics, University of Wisconsin, 1685 Highland Avenue, Room 6170-110, Madison, WI 53705-2281, USA * Corresponding author. E-mail address: [email protected] Pediatr Clin N Am 61 (2014) 1095–1107 http://dx.doi.org/10.1016/j.pcl.2014.08.008 pediatric.theclinics.com 0031-3955/14/$ – see front matter Ó 2014 Elsevier Inc. All rights reserved.
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child’s hip will not develop normally if it remains unstable and anatomically abnormal by walking age. Therefore, careful physical examination of all infants to diagnosis and treat significant DDH is critical to provide the best possible functional outcome. Regardless of the practice setting, all health professionals who care for newborns and infants should be trained to evaluate the infant hip for instability and provide appropriate and early conservative treatment or referral. Unfortunately, musculoskeletal training in primary care residency programs and postgraduate education has received less attention than the prevalence of the condition warrants. Despite a normal newborn and infant hip examination, a late-onset hip dislocation still occurs in approximately 1 in 5000 infants as well as dysplasia in young adults. INCIDENCE AND RISK FACTORS
The incidence of DDH varies from 1.5 to 25.0 per 1000 live births, depending on the criteria used for diagnosis, the population studied, and the method of screening. Relative risk rates are stated in the American Academy of Pediatrics’ (AAP) 2000 clinical practice guidelines, and the overall DDH risk is about 1 per 1000. Traditional risk factors for DDH include breech position, female sex, being the first born, and a positive family history. Breech presentation is probably the most important single risk factor, with DDH reported in 2% to 20% of male and female infants presenting in the breech position.1,2 Frank breech in a girl, with the hips flexed and knees extended, seems to have the highest risk. However, approximately 75% of DDH occurs in female infants without any other identified risk factors, so a careful physical examination of all infants’ hips is required.1 The risk for DDH also depends on environmental factors. Newborn infants have hip and knee flexion contractures because of their normal intrauterine position. These contractures resolve over time with normal developmental maturation. Animal studies have shown that forced hip and knee extension in the neonatal period leads to hip dysplasia and dislocation because of increased tension in the hamstring and iliopsoas muscles that stresses the hip capsule, which may have underlying laxity or instability.3 Comprehensive ultrasound screening during the immediate newborn period has demonstrated hip laxity in approximately 15% of infants.4,5 The combination of capsular laxity and abnormal muscle tension is the most likely mechanism of DDH for infants who are maintained with the lower extremities extended and wrapped tightly together. In contrast, cultures that carry their children in the straddle or jockey position, common in warmer climates, have very low rates of hip dislocation compared with cultures that wrap their infants tightly with the lower limbs together and extended (Fig. 1).6 NATURAL HISTORY
The natural history of mild dysplasia and instability noted in the first few weeks of life is typically benign, with up to 88% resolving by 8 weeks of age.7 However, the natural history of a child’s hip that remains subluxated or dislocated by walking age is poor. Normal development of the hip joint depends on a femoral head that is stable and concentrically reduced in the acetabulum, a requirement for both to form spherically. Looseness or laxity within the acetabulum is termed instability. A nonconcentric position is termed subluxation. The deformity of the femoral head and acetabulum is termed dysplasia. With dislocation or severe subluxation, during the second half of infancy and beyond, limited hip abduction occurs, which the parent may notice during diaper change. As the child reaches walking age, a limp and lower-limb-length discrepancy may be apparent.
Treatment of Developmental Hip Dysplasia
Fig. 1. A 10-month-old infant positioned in front of mother with her hips widely abducted. This position is safe for the hips, avoids stresses that could cause the hip to dislocate or subluxate, and encourages stable and concentric hip development.
With maturity and later in adulthood, patients may develop pain and degenerative arthritis in the hip, knee, and low back. Hip dysplasia, subluxation, and dislocation each have their own natural history. Subluxation may not be as well tolerated as dislocation if arthritis develops in early adulthood from excessive cartilage contact pressure. A completely dislocated hip with the femoral head located in the soft tissue may not cause functional problems other than knee or back pain or limp with limb-length discrepancy if the dislocation is unilateral. Completely dislocated hips, if bilateral with the femoral heads located in the soft tissues, may lead to severe waddling gait but can likewise be surprisingly pain free. Dislocated hips in which the femoral head cartilage is in contact with the bony pelvis may develop early arthritis by the fourth or later decades because of excessive wear of the femoral head cartilage on the pelvic bone. When arthritis develops in early adulthood, the burden of disability is high, with many requiring complex hip replacement at an early age. Over time, other diseases of the hip may occur and confound the natural history and outcome. These diseases includes trauma to the hip, infection, sickle cell disease, Perthes disease, slipped capital femoral epiphysis, and tuberculosis in resource-poor countries.8 SCREENING FOR DEVELOPMENTAL DYSPLASIA OF THE HIP
Screening for DDH is important because the condition may be initially occult, is easily treated when caught early, but difficult to treat later. When detected late, it may lead to long-term disability. Although detection in the neonatal period is ideal, a reasonable goal is to detect the subluxated or dislocated hip by 6 months of age. The physical
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examination is by far the most important means of detection. Radiography or sonography imaging should be used to confirm the suspicion of DDH. Despite all current methods of screening for DDH, most young adults with dysplasia who require a hip arthroplasty are not detected at birth.9 PHYSICAL EXAMINATION
A proper examination of infants includes observation for lower-limb-length discrepancy, asymmetric thigh or gluteal folds, Ortolani sign or maneuver, and limited or asymmetric abduction.10 The Ortolani maneuver, in which a subluxated or dislocated femoral head is gently reduced into the acetabulum with hip abduction by the examiner, is the most important clinical test for detecting dysplasia in the newborn.11 The Ortolani maneuver is a continuous smooth examination starting with the hip flexed and adducted with gentle anterior pressure on the trochanter followed by gently abducting the hip while sensing (termed Segno dello scotto) whether the hip slips into the acetabulum over the hypertrophied articular cartilage (Video 1). It answers the essential question: Is the femoral head dislocated and can it be reduced into the acetabulum? The examiner should not forcefully attempt to dislocate the femoral head. Although the Ortolani sign represents the palpable sensation of the femoral head moving into the acetabulum over the hypertrophied rim of the acetabular cartilage (termed the neolimbus), isolated high-pitched clicks represent the movement of myofascial tissues from the trochanter, knee, or other soft tissue.12 By about 3 months of age, a dislocated hip may become less mobile on physical examination, thus, limiting the usefulness and sensitivity of the Ortolani maneuver. However, at this time, restricted, asymmetric hip abduction becomes an important finding of hip dysplasia. Diagnosing bilateral DDH in older infants can be difficult because of the symmetry present when there is bilateral limited hip abduction. Other signs of a dislocated hip that are noticeable as infants reach walking age are a proximal thigh crease, a positive Galeazzi sign (in which the hips and knees are flexed 90 and the knee on the dislocated side appears lower), a wider-appearing perineum, a more prominent hip curvature, and a more proximally located posterior knee crease. By walking age, infants may have a delay in walking, a Trendelenburg limp, and a bilateral waddling gait if both hips are dislocated. On the other hand, mild hip dysplasia may have no symptoms or physical findings in infants or older children. RADIOGRAPHY
Plain radiography becomes most useful by 4 to 6 months of age, when the femoral head’s secondary center of ossification (ossific nucleus) forms, a finding that occurs earlier in female infants.13 A single anteroposterior (AP) view of the entire pelvis is obtained, with positioning of the pelvis without rotation (Fig. 2). Acetabular dysplasia, subluxation, and dislocation are easily detected on the radiographs if taken after the femoral head’s ossific nucleus has appeared. If subluxation or dislocation is noted, an AP view of the pelvis with the hips abducted can be done to document hip reducibility. However, there is debate whether minor radiographic variability in young infants (increased acetabular index) constitutes actual disease.14 Radiographic hip screening is traditionally indicated for infants with risk factors, such as a history of breech presentation or an abnormal physical examination at 4 months of age.2,10,15,16 An AP radiograph of the pelvis is obtained in newborns or infants if other conditions, such as congenital short femur, proximal focal femoral deficiency, septic hip infection, or coxa vara, are suspected.
Treatment of Developmental Hip Dysplasia
Fig. 2. AP radiograph of a 6-month-old infant. Note the dysplasia of the left hip with delayed ossific nucleus, superior and lateral dislocation, and small steep acetabulum.
ULTRASONOGRAPHY
The American Institute of Ultrasound in Medicine (AIUM) and the American College of Radiology (ACR) have published a joint guideline for the standardized performance of the infantile hip ultrasound.17 Ultrasonography can provide detailed static and dynamic imaging of the hip before femoral head ossification. Ultrasound hip imaging can be universal for all infants or selective for those at risk for having DDH. Because disease prevalence is low at 1% to 2%, universal ultrasound screening is not generally practiced in North America or in countries with limited resources. Many barriers to successful ultrasound screening programs in the United States include expense, lack of availability, lack of trained personnel to assure quality imaging and interpretation, inconvenience, subjectivity, a high false-positive rate, and controversy about effectiveness. Universal ultrasound screening of all infants is practiced in many European countries, with programs typically showing a decrease in the number of hips needing surgical reduction after their programs were begun. Most recently, a large randomized controlled study of universal or selective ultrasound screening in Norway that was compared with a well-done physical examination showed higher treatment rates but no significant decrease in late cases of DDH.18 This same group of patients who underwent ultrasound screening and were followed to skeletal maturity did not have less acetabular dysplasia or degenerative change, although there was also no increased rate of avascular necrosis.18 Despite this screening program for DDH, 92% of young adults with hip dysplasia who required a total hip arthroplasty were not detected at birth.9 Results of these quality studies indicate that a well-performed physical examination in infants is the most important means of detecting instability; however, dysplasia is currently undetectable at birth for many adults. In countries with very limited resources, even selective ultrasound screening is not typically available. The lack of ultrasound screening in low-income countries does not necessarily restrict the delivery of quality care for detecting and treating DDH. In these countries, primary prevention through education about proper swaddling, early detection with a properly performed physical examination by trained health care workers and early safe conservative treatment are the basis of an effective DDH program. Similar to the emphasis on conservative clubfoot treatment in countries with limited resources, education, primary prevention, early detection and treatment are need to
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be developed (http://hipdysplasia.org). Despite successful early prevention, undetected genetically determined acetabular dysplasia may still present in the young adult.19 Ultrasound screening should not be performed before 3 to 4 weeks of age in infants with clinical signs or risk factors for DDH because of the normal physiologic laxity that typically resolves by 6 weeks of age.17 Most minor sonographic hip anomalies seen at 4 weeks to 4 months of age will resolve spontaneously. These anomalies include minor changes in morphology and subluxation (uncoverage) with stress maneuvers. Proper timing, performance, and interpretation of infantile hip ultrasound imaging per the guidelines of the AIUM and the ACR is critical to avoid undertreatment or overtreatment. If available, ultrasound imaging can be used to guide the reduction of a dislocated hip in infants who are being treated in a Pavlik harness or other hip abduction orthosis (Fig. 3). With the current medicolegal climate that fosters defensive medicine, widespread ultrasonography has become the default ordered test, resulting in excessive referral and treatment as well as poor use of limited resources for infants with very mild dysplasia or laxity.20,21 Developing local/regional criteria for screening imaging and referral based on best resources, especially for ultrasonography, should promote more uniform and cost-effective treatment. SWADDLING
Traditional swaddling that is still practiced in many cultures with the lower extremities fully extended and wrapped together can cause hip subluxation and dislocation (Fig. 4). Studies of Native Americans before the 1950s demonstrated a very high prevalence of hip dislocation in communities when their babies were carried on a cradleboard with the hips and knees strapped in an extended and adducted position. The frequency of childhood hip dislocation decreased dramatically among Navajo infants after cloth diapers were introduced. This decrease in the incidence of hip dislocation
Fig. 3. Ultrasound of hip. (1) Femoral head, (2) acetabulum, (3) lateral border of ilium, (4) labrum, (5) abductor muscles. Arrow points to the triradiate cartilage.
Treatment of Developmental Hip Dysplasia
Fig. 4. Infant in traditional cradleboard. Infants would spend much of their time in this devise with hips tightly bound. Over time, the swaddling has become less tight; infants now wear diapers, and time in the cradleboard has decreased in favor of car seats and other carriers. As a result, the prevalence of DDH in the Navajo population, which previously was 6 times the US national average, is now similar.
among Navajo infants was attributed to the slightly flexed and abducted position from the bulky cloth diapers even when the infants were strapped on the cradleboard. Recently, as the frequency of cradleboard use and time spent in the cradleboard in Navajo society has diminished, so has the prevalence of hip dysplasia, from a rate of 6 times the US average to a prevalence similar to the rest of the US population. A similar experience has been documented in Japan where the incidence of DDH was 1.5% to 3.5% before 1965. Following the implementation of a national program to eliminate swaddling with the hips and knees in an extended position, the incidence of DDH decreased to 0.2%.3 A significant relationship between swaddling and hip dysplasia was also identified in Turkey.22 Although the frequency of traditional swaddling has been reduced in Turkey, traditional swaddling during infancy is still the greatest risk factor compared with breech birth, family history, or sex.23 A systematic review of swaddling noted that DDH is more prevalent when the lower limbs are bound so they are not free to move.24 Despite the known risks to the tightly bound hip, swaddling has grown in popularity among parents in the United States and internationally. The concept of safe swaddling, which does not restrict hip motion but rather allows the hips to remain in the human or naturally flexed and abducted position, has been shown to lessen the risk of DDH.24–31 The International Hip Dysplasia Institute and the Pediatric Orthopedic Society of North America have issued the following statement about the safety of swaddling: Infant hips should be positioned in slight flexion and abduction during swaddling. The knees should also be maintained in slight flexion. Additional free movement in the direction of hip flexion and abduction may have some benefit [http:// hipdysplasia.org]. Avoidance of forced or sustained passive hip extension and adduction in the first few months of life is essential for proper hip development. Contemporary methods of swaddling emphasize upper extremity wrapping while allowing ample room for hip and knee flexion (Fig. 5) (video available at http:// hipdysplasia.org/developmental-dysplasia-of-the-hip/hip-healthy-swaddling/).32 Prevention of DDH should begin with encouragement of flexed and abducted hip
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Fig. 5. Safe swaddling technique. Notice that while the upper extremities are securely wrapped, the hips and lower extremities are free to move with hip flexion and abduction.
positioning during early infancy in all infants. Infants who have been swaddled tightly with the hips and legs bound together in extension should have a focused attention to their periodic clinical hip examination and treating physicians need to have a frank discussion with their parents regarding safe swaddling technique. TREATMENT
Early detection and referral of DDH allows appropriate intervention with bracing or casting, which, for most treated infants, may safely prevent the need for reconstructive surgery. It is likely that a primary care physician or health care worker will be the first to detect hip dysplasia, so all who care for newborns and infants in the primary care setting need proper training in the diagnosis and appropriate referral of these children. The physical examination, despite advances in ultrasound imaging, remains the most important screening tool, especially because most infants with DDH have no identified risk factors other than female sex.33–35 In a study of children on the US Navajo Reservation that used the AAP’s guidelines, most significant DDH was detected by a competent newborn physical examination performed by a pediatrician or general practitioner.10,16 The more severe the instability, the more useful was the physical examination in detecting DDH.36 In a decision analysis model, the lowest probability of developing degenerative disease of the hip by 60 years of age was doing a thorough physical examination of the hip on all newborns.37 Any infant with a positive Ortolani maneuver should be closely followed or referred for evaluation. An infant with a persistent positive Ortolani maneuver on repeat examination should be referred for treatment. An infant with limited or asymmetric abduction should receive an ultrasound examination if younger than 4 to 6 months, or a radiograph if older, with treatment provided for children with a dislocated or subluxated hip. Periodic physical examination should be performed and documented on all children until walking age.10 If the newborn hip is not clinically stable by 3 weeks of age, treatment with a hip abduction devise, such as a Pavlik harness or von Rosen splint, is recommended. These devices can be used for infants who are up to 6 months of age and are typically managed by an orthopedic surgeon who has training, interest, and expertise in DDH. The goal of treatment is to use an orthosis until the hip is documented by physical examination and ultrasound imaging to be stable. Serial ultrasonography and radiography are used by the treating orthopedist to determine the efficacy of treatment. If Pavlik harness treatment is used, precautions, such as avoiding forced abduction, stopping treatment after 3 weeks if the hip does not reduce, and proper strap
Treatment of Developmental Hip Dysplasia
placement with weekly monitoring, is important to minimize the small risks that are associated with this treatment. After the hip has become stable in the Pavlik harness, longer treatment with the harness or a hip abduction orthosis is typically used until the acetabulum morphology is normalized. The older the child is at the time of treatment, the longer treatment may assure stability and normalization of acetabular morphology. Although up to 90% of hips in newborns or young infants can be successfully treated with a Pavlik harness, not all hips become stable. Closed reduction and casting may be needed if the hip does not become stable by 3 weeks of Pavlik harness treatment. After 6 months of age, surgical treatment with arthrogram, adductor tenotomy, and spica cast is an effective conservative approach for children with a dislocated hip to achieve a concentric closed reduction. After children have achieved walking ability, open reduction of the hip is often required because of the development of fixed contractures and deformity that respond less predictably to closed reduction. This procedure is specialized surgery and should be performed by an orthopedic surgeon with the appropriate level of training, experience, and expertise. The risks of bracing, casting, and surgical treatment may include avascular necrosis (AVN), nonconcentric reduction, redislocation, femoral nerve palsy, and obturator (inferior) hip dislocation.38–40 The risk of AVN is higher in older children who need surgical treatment than with a conservative Pavlik harness or brace treatment in infants. The increased risk with late treatment compared with early treatment reinforces the principle of early screening and treatment over later surgical management. Regardless of the method used, reduction of the hip should never be forced or held in an extreme position.41,42 Surgical treatment in the infant and young child has the added risks of anesthesia, infection, redislocation, stiffness and later arthritis. Long term, all children with a history of DDH should be followed until skeletal maturity. In countries with limited resources, even in the United States or other developed countries, children may present with DDH after walking age. A 3-year-old child who presents with a unilateral dislocated hip may have a reasonable outcome after open reduction, femoral shortening, and acetabular osteotomy, if the surgery is precisely performed, the reduction is gentle and concentric, stability is maintained, and AVN is either avoided or minimalized. Although there is no exact age cutoff for when
Fig. 6. Bilateral high hip dislocation in a 10-year-old child. Bilateral dislocations, because of symmetry, may be more difficult to detect in infants or young children. It is a reasonable goal for the primary care physician to prevent hip subluxation or dislocation by 6 months of age using the periodic examination.
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children are too old for surgical treatment, as children become older than 3 years, results will deteriorate with increasing age of surgery.43 Castaneda and colleagues44 reported that the long-term results of Iowa Hip Score, PODCI (Pediatric Outcomes Data Collection Instrument), hip centering, and radiographic hip morphology diminished with the age at the time of surgery. A unilateral hip dislocation in a 5 year old with well-preserved hip morphology may do well if surgery is expertly performed. However, bilateral open hip reductions in an 8 year old with highly dysplastic acetabula and femoral heads will likely have poor long-term outcome from the surgery and is best left untreated (Fig. 6). Besides a generally worse outcome in older children, the additional complications of osteonecrosis and redislocation predict the poorest results.43 Half of surgically reduced hips may still require further surgery. Even the opposite normal hip may eventually show significant dysplasia, suggesting a genetic cause. Once surgery
Box 1 Summary statement and recommendations The following recommendations have been developed by the DDH Task Force of the AAP Section on Orthopedics: 1. Tight swaddling of the lower extremities with the hips extended should be avoided. The concept of safe swaddling, which does not restrict hip motion, minimizes the risk for DDH. 2. The AAP, the Pediatric Orthopaedic Society of North America, the American Academy of Orthopaedic Surgeons, and the Canadian DDH Task Force recommend newborn and periodic screening examinations for DDH to include evaluating for positive Ortolani maneuver in newborns and young infants, detection of limb-length discrepancy, asymmetric thigh or buttock (gluteal) creases, limited abduction (generally positive after 3 months of age) and associated findings of torticollis, ligamentous laxity, and foot deformity. 3. Evidence strongly supports screening for and treatment of hip subluxation and dislocation (Ortolani positive) and observation of milder early forms of dysplasia and instability (Barlow positive). 4. It is acceptable to refer children with suspected DDH or with positive risk factors to a pediatric orthopedist without a prior ultrasound, which is preferable to obtaining an improperly timed or poorly performed study. 5. Treatment of neonatal DDH is not an emergency. In-hospital initiation of bracing by the primary care physician or other health professional is not required if infants with persistent instability are referred to the orthopedic surgeon within several weeks. Initiation of treatment is based on the clinical examination of instability. 6. Ultrasonography can be useful between 4 weeks and 4 to 6 months of age for infants with risk factors for DDH. These risk factors include clinical instability, breech presentation, and positive family history. Other considerations for imaging studies, especially if there is a persistent concern about the clinical examination include first-born girls, parental concern, and a history of improperly performed lower extremity swaddling. 7. Radiography (AP and frog lateral pelvis views) is useful after 4 to 6 months of age for infants with risk factors or positive clinical findings. There is a period between 4 and 6 months of age when either a radiograph or ultrasound imaging can be used. 8. A reasonable goal for the primary care physician should be to prevent hip subluxation or dislocation by 6 months of age using the periodic examination. Selective ultrasonography or radiography is used in consultation with the pediatric radiologist and orthopedist. Screening programs have not completely eliminated the risk of a late presentation of DDH. Milder forms of dysplasia may resolve spontaneously or with early treatment. However, dysplasia that may require arthroplasty in young adults has not been completely prevented by screening and early treatment.
Treatment of Developmental Hip Dysplasia
has failed and revision is contemplated, this repeat surgery in older children has very poor overall long-term results (Box 1). SUPPLEMENTARY DATA
Supplementary data related to this article can be found online at http://dx.doi.org/10. 1016/j.pcl.2014.08.008. REFERENCES
1. Bache CE, Clegg J, Herron M. Risk factors for developmental dysplasia of the hip: ultrasonographic findings in the neonatal period. J Pediatr Orthop B 2002; 11(3):212–8. 2. Imrie M, Scott V, Stearns P, et al. Is ultrasound screening for DDH in babies born breech sufficient? J Child Orthop 2010;4(1):3–8. 3. Yamamuro T, Ishida K. Recent advances in the prevention, early diagnosis, and treatment of congenital dislocation of the hip in Japan. Clin Orthop Relat Res 1984;184:34–40. 4. Rosendahl K, Markestad T, Lie RT. Ultrasound screening for developmental dysplasia of the hip in the neonate: the effect on treatment rate and prevalence of late cases. Pediatrics 1994;94:47–52. 5. US Preventive Services Task Force. Screening for developmental dysplasia of the hip: recommendation statement. Pediatrics 2006;117:898–902. 6. Salter RB. Etiology, pathogenesis and possible prevention of congenital dislocation of the hip. Can Med Assoc J 1968;98:933–45. 7. Barlow TG. Early diagnosis and treatment of congenital dislocation of the hip. J Bone Joint Surg Br 1962;44B:292–301. 8. Oniankitan O, Kakpovi K, Flanyo E, et al. Risk factors for hip osteoarthritis in Lome, Togo. Med Trop (Mars) 2009;69(1):59–60. 9. Engesaeter IO, Lie SA, Lehmann TG, et al. Neonatal hip instability and risk of total hip replacement in young adulthood: follow-up of 2,218,596 newborns from the Medical Birth Registry of Norway in the Norwegian Arthroplasty Register. Acta Orthop 2008;79(3):321–6. 10. Committee on Quality Improvement, Subcommittee on Developmental Dysplasia of the Hip. American Academy of Pediatrics: clinical practice guideline: early detection of developmental dysplasia of the hip. Pediatrics 2000;105:896–905. 11. Lipton GE, Guille JT, Altiok H, et al. A reappraisal of the Ortolani examination in children with developmental dysplasia of the hip. J Pediatr Orthop 2007;27(1):27–31. 12. Bond CD, Hennrikus WL, DellaMaggiore ED. Prospective evaluation of newborn soft-tissue hip “clicks” with ultrasound. J Pediatr Orthop 1997;17(2):199–201. 13. Scoles PV, Boyd A, Jones PK. Radiographic parameters of the normal infant hip. J Pediatr Orthop 1987;7(6):656–63. 14. Mladenov K, Dora C, Wicart P, et al. Natural history of hips with borderline acetabular index and acetabular dysplasia in infants. J Pediatr Orthop 2002;22(5): 607–12. 15. Karmazyn BK, Gunderman RB, Coley BD, et al. American College of Radiology ACR Appropriateness Criteria on developmental dysplasia of the hip—child. J Am Coll Radiol 2009;6(8):551–7. 16. Schwend RM, Schoenecker P, Richards BS, et al. Pediatric Orthopaedic Society of North America Screening the newborn for developmental dysplasia of the hip: now what do we do? J Pediatr Orthop 2007;27:607–10.
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17. American Institute of Ultrasound in Medicine, American College of Radiology. AIUM practice guideline for the performance of an ultrasound examination for detection and assessment of developmental dysplasia of the hip. J Ultrasound Med 2009;28(1):114–9. 18. Laborie LB, Engesaiter IO, Lehmann TG, et al. Screening strategies for hip dysplasia: long-term outcome of a randomized controlled trial. Pediatrics 2013; 132(3):492–501. 19. Schwend RM, Pratt WB, Fultz J. Untreated acetabular dysplasia of the hip in the Navajo. A 34 year case series follow-up. Clin Orthop Relat Res 1999;(364):108–16. 20. Elbourne D, Dezateux C, Arthur R, et al. Ultrasonography in the diagnosis and management of developmental hip dysplasia (UK Hip Trial): clinical and economic results of a multicentre randomized controlled trial. Lancet 2002;360(9350):2009–17. 21. Moore FH. Examining infants’ hips – can it do harm? J Bone Joint Surg Br 1989; 71B:4–5. 22. Kutlu A, Memik R, Mutlu M, et al. Congenital dislocation of the hip and its relation to swaddling used in Turkey. J Pediatr Orthop 1992;12:598–602. 23. Dogruel H, Atalar H, Yavuz OY, et al. Clinical examination versus ultrasonography in detecting developmental dysplasia of the hip. Int Orthop 2008;32(3):415–9. 24. van Sleuwen BE, Engelberts AC, Boere-Boonekamp MM, et al. Swaddling: a systematic review. Pediatrics 2007;120:e1097–106. 25. Gerard CM, Harris KA, Thach BT. Physiologic studies on swaddling: an ancient child care practice, which may promote the supine position for infant sleep. J Pediatr 2002;141:398–403. 26. Mahan ST, Kasser JR. Does swaddling influence developmental dysplasia of the hip? Pediatrics 2008;121:177–8. 27. Oden RP, Powell C, Sims A, et al. Swaddling: will it get babies onto their backs for sleep? Clin Pediatr 2012;51:254–9. 28. Wang E, Liu T, Li J, et al. Does swaddling influence developmental dysplasia of the hip. J Bone Joint Surg Am 2012;94:1071–7. 29. International Hip Dysplasia Institute (Online resources). Available at: http:// hipdysplasia.org. Accessed on July 1, 2014. 30. American Academy of Orthopaedic Surgeons (Online resources). Available at: http://orthoinfo.aaos.org/topic.cfm?topic5A00347. Accessed on July 1, 2014. 31. Pediatric Orthopaedic Society of North America (Online resources). Available at: http://posna.org/. Accessed on July 1, 2014. 32. Karp HN. Safe swaddling and healthy hips: don’t toss the baby out with the bathwater. Pediatrics 2008;121:1075–6. 33. Jones DA. Neonatal hip stability and the Barlow test. J Bone Joint Surg Br 1991; 73B:216–8. 34. Patel H. Canadian Task Force on Preventive Health Care, 2001 update: screening and management of developmental dysplasia of the hip in newborns. Can Med Assoc J 2001;164:1669–77. 35. Shipman SA, Helfand M, Moyer VA, et al. Screening for developmental dysplasia of the hip: a systematic literature review for the U.S. Preventive Services Task Force. Pediatrics 2006;117:e557–76. 36. Schwend MR, Schooley A. The ship rock developmental dysplasia of the hip screening project. 37th Annual Carrie Tingley Winter Seminar. University of New Mexico. Albuquerque (New Mexico), February 2, 2007. 37. Mahan ST, Katz JN, Kim YJ. To screen or not to screen? A decision analysis of the utility of screening for developmental dysplasia of the hip. J Bone Joint Surg Am 2009;91(7):1705–19.
Treatment of Developmental Hip Dysplasia
38. Suzuki S, Kashiwagi N, Kasahara Y, et al. Avascular necrosis and the Pavlik harness. The incidence of avascular necrosis in three types of congenital dislocation of the hip as classified by ultrasound. J Bone Joint Surg Br 1996;78(4):631–5. 39. Murnaghan ML, Browne RH, Sucato DJ, et al. Femoral nerve palsy in Pavlik harness treatment for developmental dysplasia of the hip. J Bone Joint Surg Am 2011;93(5):493–9. 40. Rombouts JJ, Kaelin A. Inferior (obturator) dislocation of the hip in neonates. A complication of treatment by the Pavlik harness. J Bone Joint Surg Br 1992; 74(5):708–10. 41. Kitoh H, Kawasumi M, Ishiguro N. Predictive factors for unsuccessful treatment of developmental dysplasia of the hip by the Pavlik harness. J Pediatr Orthop 2009; 29(6):552–7. 42. Mubarak S, Garfin S, Vance R, et al. Pitfalls in the use of the Pavlik harness for treatment of congenital dysplasia, subluxation, and dislocation of the hip. J Bone Joint Surg Am 1981;63(8):1239–48. 43. Holman J, Carrroll KL, Murray KA, et al. Long-term follow-up of open reduction surgery for developmental dislocation of the hip. J Pediatr Orthop 2012;32(2):121–4. 44. Castan˜eda P, Arana E, Haces F, et al. Functional and radiographic results of surgical treatment of patients with neglected developmental dysplasia of the hip. Albuquerque (New Mexico): POSNA; 2008.
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, Brian A. Shaw,
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*, Lee S. Segal,
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KEYWORDS Developmental hip dysplasia Acetabular dysplasia Hip subluxation Hip dislocation Ortolani maneuver Swaddling KEY POINTS Research over the past decade has reinforced most of the principles and recommendations of the 2000 American Academy of Pediatrics’ Clinical Practice Guideline: Early Detection of Developmental Dysplasia of the Hip. A reasonable goal for the primary care physician should be to prevent hip subluxation or dislocation by 6 months of age using the periodic examination. The Ortolani maneuver, in which a subluxated or dislocated femoral head is gently reduced into the acetabulum with hip abduction by the examiner, is the most important clinical test for detecting dysplasia in the newborn. Safe swaddling, in which the hips are not extended and does not restrict hip motion, does not increase the risk for developmental hip dysplasia. Despite best practice, young adults will still present with hip dysplasia that was not detected at birth.
Video of the Ortolani maneuver accompanies this article at http:// www.pediatric.theclinics.com/ INTRODUCTION
Developmental dysplasia of the hip (DDH) encompasses a spectrum of physical and imaging findings, ranging from mild temporary instability to frank dislocation. The Disclosure: none. a Orthopaedics and Pediatrics, UMKC, KUMC Director of Research Children’s Mercy Hospital, 2401 Gillham Road, Kansas City, MO 64108, USA; b Orthopaedic Surgery, University of Colorado School of Medicine, Children’s Hospital Colorado and Memorial Health System, Colorado Springs, 4125 Briargate Parkway, Suite 100, Colorado Springs, CO 80920, USA; C Department of Orthopaedics, University of Wisconsin Hospital and Clinics, University of Wisconsin, 1685 Highland Avenue, Room 6170-110, Madison, WI 53705-2281, USA * Corresponding author. E-mail address: [email protected] Pediatr Clin N Am 61 (2014) 1095–1107 http://dx.doi.org/10.1016/j.pcl.2014.08.008 pediatric.theclinics.com 0031-3955/14/$ – see front matter Ó 2014 Elsevier Inc. All rights reserved.
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child’s hip will not develop normally if it remains unstable and anatomically abnormal by walking age. Therefore, careful physical examination of all infants to diagnosis and treat significant DDH is critical to provide the best possible functional outcome. Regardless of the practice setting, all health professionals who care for newborns and infants should be trained to evaluate the infant hip for instability and provide appropriate and early conservative treatment or referral. Unfortunately, musculoskeletal training in primary care residency programs and postgraduate education has received less attention than the prevalence of the condition warrants. Despite a normal newborn and infant hip examination, a late-onset hip dislocation still occurs in approximately 1 in 5000 infants as well as dysplasia in young adults. INCIDENCE AND RISK FACTORS
The incidence of DDH varies from 1.5 to 25.0 per 1000 live births, depending on the criteria used for diagnosis, the population studied, and the method of screening. Relative risk rates are stated in the American Academy of Pediatrics’ (AAP) 2000 clinical practice guidelines, and the overall DDH risk is about 1 per 1000. Traditional risk factors for DDH include breech position, female sex, being the first born, and a positive family history. Breech presentation is probably the most important single risk factor, with DDH reported in 2% to 20% of male and female infants presenting in the breech position.1,2 Frank breech in a girl, with the hips flexed and knees extended, seems to have the highest risk. However, approximately 75% of DDH occurs in female infants without any other identified risk factors, so a careful physical examination of all infants’ hips is required.1 The risk for DDH also depends on environmental factors. Newborn infants have hip and knee flexion contractures because of their normal intrauterine position. These contractures resolve over time with normal developmental maturation. Animal studies have shown that forced hip and knee extension in the neonatal period leads to hip dysplasia and dislocation because of increased tension in the hamstring and iliopsoas muscles that stresses the hip capsule, which may have underlying laxity or instability.3 Comprehensive ultrasound screening during the immediate newborn period has demonstrated hip laxity in approximately 15% of infants.4,5 The combination of capsular laxity and abnormal muscle tension is the most likely mechanism of DDH for infants who are maintained with the lower extremities extended and wrapped tightly together. In contrast, cultures that carry their children in the straddle or jockey position, common in warmer climates, have very low rates of hip dislocation compared with cultures that wrap their infants tightly with the lower limbs together and extended (Fig. 1).6 NATURAL HISTORY
The natural history of mild dysplasia and instability noted in the first few weeks of life is typically benign, with up to 88% resolving by 8 weeks of age.7 However, the natural history of a child’s hip that remains subluxated or dislocated by walking age is poor. Normal development of the hip joint depends on a femoral head that is stable and concentrically reduced in the acetabulum, a requirement for both to form spherically. Looseness or laxity within the acetabulum is termed instability. A nonconcentric position is termed subluxation. The deformity of the femoral head and acetabulum is termed dysplasia. With dislocation or severe subluxation, during the second half of infancy and beyond, limited hip abduction occurs, which the parent may notice during diaper change. As the child reaches walking age, a limp and lower-limb-length discrepancy may be apparent.
Treatment of Developmental Hip Dysplasia
Fig. 1. A 10-month-old infant positioned in front of mother with her hips widely abducted. This position is safe for the hips, avoids stresses that could cause the hip to dislocate or subluxate, and encourages stable and concentric hip development.
With maturity and later in adulthood, patients may develop pain and degenerative arthritis in the hip, knee, and low back. Hip dysplasia, subluxation, and dislocation each have their own natural history. Subluxation may not be as well tolerated as dislocation if arthritis develops in early adulthood from excessive cartilage contact pressure. A completely dislocated hip with the femoral head located in the soft tissue may not cause functional problems other than knee or back pain or limp with limb-length discrepancy if the dislocation is unilateral. Completely dislocated hips, if bilateral with the femoral heads located in the soft tissues, may lead to severe waddling gait but can likewise be surprisingly pain free. Dislocated hips in which the femoral head cartilage is in contact with the bony pelvis may develop early arthritis by the fourth or later decades because of excessive wear of the femoral head cartilage on the pelvic bone. When arthritis develops in early adulthood, the burden of disability is high, with many requiring complex hip replacement at an early age. Over time, other diseases of the hip may occur and confound the natural history and outcome. These diseases includes trauma to the hip, infection, sickle cell disease, Perthes disease, slipped capital femoral epiphysis, and tuberculosis in resource-poor countries.8 SCREENING FOR DEVELOPMENTAL DYSPLASIA OF THE HIP
Screening for DDH is important because the condition may be initially occult, is easily treated when caught early, but difficult to treat later. When detected late, it may lead to long-term disability. Although detection in the neonatal period is ideal, a reasonable goal is to detect the subluxated or dislocated hip by 6 months of age. The physical
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examination is by far the most important means of detection. Radiography or sonography imaging should be used to confirm the suspicion of DDH. Despite all current methods of screening for DDH, most young adults with dysplasia who require a hip arthroplasty are not detected at birth.9 PHYSICAL EXAMINATION
A proper examination of infants includes observation for lower-limb-length discrepancy, asymmetric thigh or gluteal folds, Ortolani sign or maneuver, and limited or asymmetric abduction.10 The Ortolani maneuver, in which a subluxated or dislocated femoral head is gently reduced into the acetabulum with hip abduction by the examiner, is the most important clinical test for detecting dysplasia in the newborn.11 The Ortolani maneuver is a continuous smooth examination starting with the hip flexed and adducted with gentle anterior pressure on the trochanter followed by gently abducting the hip while sensing (termed Segno dello scotto) whether the hip slips into the acetabulum over the hypertrophied articular cartilage (Video 1). It answers the essential question: Is the femoral head dislocated and can it be reduced into the acetabulum? The examiner should not forcefully attempt to dislocate the femoral head. Although the Ortolani sign represents the palpable sensation of the femoral head moving into the acetabulum over the hypertrophied rim of the acetabular cartilage (termed the neolimbus), isolated high-pitched clicks represent the movement of myofascial tissues from the trochanter, knee, or other soft tissue.12 By about 3 months of age, a dislocated hip may become less mobile on physical examination, thus, limiting the usefulness and sensitivity of the Ortolani maneuver. However, at this time, restricted, asymmetric hip abduction becomes an important finding of hip dysplasia. Diagnosing bilateral DDH in older infants can be difficult because of the symmetry present when there is bilateral limited hip abduction. Other signs of a dislocated hip that are noticeable as infants reach walking age are a proximal thigh crease, a positive Galeazzi sign (in which the hips and knees are flexed 90 and the knee on the dislocated side appears lower), a wider-appearing perineum, a more prominent hip curvature, and a more proximally located posterior knee crease. By walking age, infants may have a delay in walking, a Trendelenburg limp, and a bilateral waddling gait if both hips are dislocated. On the other hand, mild hip dysplasia may have no symptoms or physical findings in infants or older children. RADIOGRAPHY
Plain radiography becomes most useful by 4 to 6 months of age, when the femoral head’s secondary center of ossification (ossific nucleus) forms, a finding that occurs earlier in female infants.13 A single anteroposterior (AP) view of the entire pelvis is obtained, with positioning of the pelvis without rotation (Fig. 2). Acetabular dysplasia, subluxation, and dislocation are easily detected on the radiographs if taken after the femoral head’s ossific nucleus has appeared. If subluxation or dislocation is noted, an AP view of the pelvis with the hips abducted can be done to document hip reducibility. However, there is debate whether minor radiographic variability in young infants (increased acetabular index) constitutes actual disease.14 Radiographic hip screening is traditionally indicated for infants with risk factors, such as a history of breech presentation or an abnormal physical examination at 4 months of age.2,10,15,16 An AP radiograph of the pelvis is obtained in newborns or infants if other conditions, such as congenital short femur, proximal focal femoral deficiency, septic hip infection, or coxa vara, are suspected.
Treatment of Developmental Hip Dysplasia
Fig. 2. AP radiograph of a 6-month-old infant. Note the dysplasia of the left hip with delayed ossific nucleus, superior and lateral dislocation, and small steep acetabulum.
ULTRASONOGRAPHY
The American Institute of Ultrasound in Medicine (AIUM) and the American College of Radiology (ACR) have published a joint guideline for the standardized performance of the infantile hip ultrasound.17 Ultrasonography can provide detailed static and dynamic imaging of the hip before femoral head ossification. Ultrasound hip imaging can be universal for all infants or selective for those at risk for having DDH. Because disease prevalence is low at 1% to 2%, universal ultrasound screening is not generally practiced in North America or in countries with limited resources. Many barriers to successful ultrasound screening programs in the United States include expense, lack of availability, lack of trained personnel to assure quality imaging and interpretation, inconvenience, subjectivity, a high false-positive rate, and controversy about effectiveness. Universal ultrasound screening of all infants is practiced in many European countries, with programs typically showing a decrease in the number of hips needing surgical reduction after their programs were begun. Most recently, a large randomized controlled study of universal or selective ultrasound screening in Norway that was compared with a well-done physical examination showed higher treatment rates but no significant decrease in late cases of DDH.18 This same group of patients who underwent ultrasound screening and were followed to skeletal maturity did not have less acetabular dysplasia or degenerative change, although there was also no increased rate of avascular necrosis.18 Despite this screening program for DDH, 92% of young adults with hip dysplasia who required a total hip arthroplasty were not detected at birth.9 Results of these quality studies indicate that a well-performed physical examination in infants is the most important means of detecting instability; however, dysplasia is currently undetectable at birth for many adults. In countries with very limited resources, even selective ultrasound screening is not typically available. The lack of ultrasound screening in low-income countries does not necessarily restrict the delivery of quality care for detecting and treating DDH. In these countries, primary prevention through education about proper swaddling, early detection with a properly performed physical examination by trained health care workers and early safe conservative treatment are the basis of an effective DDH program. Similar to the emphasis on conservative clubfoot treatment in countries with limited resources, education, primary prevention, early detection and treatment are need to
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be developed (http://hipdysplasia.org). Despite successful early prevention, undetected genetically determined acetabular dysplasia may still present in the young adult.19 Ultrasound screening should not be performed before 3 to 4 weeks of age in infants with clinical signs or risk factors for DDH because of the normal physiologic laxity that typically resolves by 6 weeks of age.17 Most minor sonographic hip anomalies seen at 4 weeks to 4 months of age will resolve spontaneously. These anomalies include minor changes in morphology and subluxation (uncoverage) with stress maneuvers. Proper timing, performance, and interpretation of infantile hip ultrasound imaging per the guidelines of the AIUM and the ACR is critical to avoid undertreatment or overtreatment. If available, ultrasound imaging can be used to guide the reduction of a dislocated hip in infants who are being treated in a Pavlik harness or other hip abduction orthosis (Fig. 3). With the current medicolegal climate that fosters defensive medicine, widespread ultrasonography has become the default ordered test, resulting in excessive referral and treatment as well as poor use of limited resources for infants with very mild dysplasia or laxity.20,21 Developing local/regional criteria for screening imaging and referral based on best resources, especially for ultrasonography, should promote more uniform and cost-effective treatment. SWADDLING
Traditional swaddling that is still practiced in many cultures with the lower extremities fully extended and wrapped together can cause hip subluxation and dislocation (Fig. 4). Studies of Native Americans before the 1950s demonstrated a very high prevalence of hip dislocation in communities when their babies were carried on a cradleboard with the hips and knees strapped in an extended and adducted position. The frequency of childhood hip dislocation decreased dramatically among Navajo infants after cloth diapers were introduced. This decrease in the incidence of hip dislocation
Fig. 3. Ultrasound of hip. (1) Femoral head, (2) acetabulum, (3) lateral border of ilium, (4) labrum, (5) abductor muscles. Arrow points to the triradiate cartilage.
Treatment of Developmental Hip Dysplasia
Fig. 4. Infant in traditional cradleboard. Infants would spend much of their time in this devise with hips tightly bound. Over time, the swaddling has become less tight; infants now wear diapers, and time in the cradleboard has decreased in favor of car seats and other carriers. As a result, the prevalence of DDH in the Navajo population, which previously was 6 times the US national average, is now similar.
among Navajo infants was attributed to the slightly flexed and abducted position from the bulky cloth diapers even when the infants were strapped on the cradleboard. Recently, as the frequency of cradleboard use and time spent in the cradleboard in Navajo society has diminished, so has the prevalence of hip dysplasia, from a rate of 6 times the US average to a prevalence similar to the rest of the US population. A similar experience has been documented in Japan where the incidence of DDH was 1.5% to 3.5% before 1965. Following the implementation of a national program to eliminate swaddling with the hips and knees in an extended position, the incidence of DDH decreased to 0.2%.3 A significant relationship between swaddling and hip dysplasia was also identified in Turkey.22 Although the frequency of traditional swaddling has been reduced in Turkey, traditional swaddling during infancy is still the greatest risk factor compared with breech birth, family history, or sex.23 A systematic review of swaddling noted that DDH is more prevalent when the lower limbs are bound so they are not free to move.24 Despite the known risks to the tightly bound hip, swaddling has grown in popularity among parents in the United States and internationally. The concept of safe swaddling, which does not restrict hip motion but rather allows the hips to remain in the human or naturally flexed and abducted position, has been shown to lessen the risk of DDH.24–31 The International Hip Dysplasia Institute and the Pediatric Orthopedic Society of North America have issued the following statement about the safety of swaddling: Infant hips should be positioned in slight flexion and abduction during swaddling. The knees should also be maintained in slight flexion. Additional free movement in the direction of hip flexion and abduction may have some benefit [http:// hipdysplasia.org]. Avoidance of forced or sustained passive hip extension and adduction in the first few months of life is essential for proper hip development. Contemporary methods of swaddling emphasize upper extremity wrapping while allowing ample room for hip and knee flexion (Fig. 5) (video available at http:// hipdysplasia.org/developmental-dysplasia-of-the-hip/hip-healthy-swaddling/).32 Prevention of DDH should begin with encouragement of flexed and abducted hip
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Fig. 5. Safe swaddling technique. Notice that while the upper extremities are securely wrapped, the hips and lower extremities are free to move with hip flexion and abduction.
positioning during early infancy in all infants. Infants who have been swaddled tightly with the hips and legs bound together in extension should have a focused attention to their periodic clinical hip examination and treating physicians need to have a frank discussion with their parents regarding safe swaddling technique. TREATMENT
Early detection and referral of DDH allows appropriate intervention with bracing or casting, which, for most treated infants, may safely prevent the need for reconstructive surgery. It is likely that a primary care physician or health care worker will be the first to detect hip dysplasia, so all who care for newborns and infants in the primary care setting need proper training in the diagnosis and appropriate referral of these children. The physical examination, despite advances in ultrasound imaging, remains the most important screening tool, especially because most infants with DDH have no identified risk factors other than female sex.33–35 In a study of children on the US Navajo Reservation that used the AAP’s guidelines, most significant DDH was detected by a competent newborn physical examination performed by a pediatrician or general practitioner.10,16 The more severe the instability, the more useful was the physical examination in detecting DDH.36 In a decision analysis model, the lowest probability of developing degenerative disease of the hip by 60 years of age was doing a thorough physical examination of the hip on all newborns.37 Any infant with a positive Ortolani maneuver should be closely followed or referred for evaluation. An infant with a persistent positive Ortolani maneuver on repeat examination should be referred for treatment. An infant with limited or asymmetric abduction should receive an ultrasound examination if younger than 4 to 6 months, or a radiograph if older, with treatment provided for children with a dislocated or subluxated hip. Periodic physical examination should be performed and documented on all children until walking age.10 If the newborn hip is not clinically stable by 3 weeks of age, treatment with a hip abduction devise, such as a Pavlik harness or von Rosen splint, is recommended. These devices can be used for infants who are up to 6 months of age and are typically managed by an orthopedic surgeon who has training, interest, and expertise in DDH. The goal of treatment is to use an orthosis until the hip is documented by physical examination and ultrasound imaging to be stable. Serial ultrasonography and radiography are used by the treating orthopedist to determine the efficacy of treatment. If Pavlik harness treatment is used, precautions, such as avoiding forced abduction, stopping treatment after 3 weeks if the hip does not reduce, and proper strap
Treatment of Developmental Hip Dysplasia
placement with weekly monitoring, is important to minimize the small risks that are associated with this treatment. After the hip has become stable in the Pavlik harness, longer treatment with the harness or a hip abduction orthosis is typically used until the acetabulum morphology is normalized. The older the child is at the time of treatment, the longer treatment may assure stability and normalization of acetabular morphology. Although up to 90% of hips in newborns or young infants can be successfully treated with a Pavlik harness, not all hips become stable. Closed reduction and casting may be needed if the hip does not become stable by 3 weeks of Pavlik harness treatment. After 6 months of age, surgical treatment with arthrogram, adductor tenotomy, and spica cast is an effective conservative approach for children with a dislocated hip to achieve a concentric closed reduction. After children have achieved walking ability, open reduction of the hip is often required because of the development of fixed contractures and deformity that respond less predictably to closed reduction. This procedure is specialized surgery and should be performed by an orthopedic surgeon with the appropriate level of training, experience, and expertise. The risks of bracing, casting, and surgical treatment may include avascular necrosis (AVN), nonconcentric reduction, redislocation, femoral nerve palsy, and obturator (inferior) hip dislocation.38–40 The risk of AVN is higher in older children who need surgical treatment than with a conservative Pavlik harness or brace treatment in infants. The increased risk with late treatment compared with early treatment reinforces the principle of early screening and treatment over later surgical management. Regardless of the method used, reduction of the hip should never be forced or held in an extreme position.41,42 Surgical treatment in the infant and young child has the added risks of anesthesia, infection, redislocation, stiffness and later arthritis. Long term, all children with a history of DDH should be followed until skeletal maturity. In countries with limited resources, even in the United States or other developed countries, children may present with DDH after walking age. A 3-year-old child who presents with a unilateral dislocated hip may have a reasonable outcome after open reduction, femoral shortening, and acetabular osteotomy, if the surgery is precisely performed, the reduction is gentle and concentric, stability is maintained, and AVN is either avoided or minimalized. Although there is no exact age cutoff for when
Fig. 6. Bilateral high hip dislocation in a 10-year-old child. Bilateral dislocations, because of symmetry, may be more difficult to detect in infants or young children. It is a reasonable goal for the primary care physician to prevent hip subluxation or dislocation by 6 months of age using the periodic examination.
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children are too old for surgical treatment, as children become older than 3 years, results will deteriorate with increasing age of surgery.43 Castaneda and colleagues44 reported that the long-term results of Iowa Hip Score, PODCI (Pediatric Outcomes Data Collection Instrument), hip centering, and radiographic hip morphology diminished with the age at the time of surgery. A unilateral hip dislocation in a 5 year old with well-preserved hip morphology may do well if surgery is expertly performed. However, bilateral open hip reductions in an 8 year old with highly dysplastic acetabula and femoral heads will likely have poor long-term outcome from the surgery and is best left untreated (Fig. 6). Besides a generally worse outcome in older children, the additional complications of osteonecrosis and redislocation predict the poorest results.43 Half of surgically reduced hips may still require further surgery. Even the opposite normal hip may eventually show significant dysplasia, suggesting a genetic cause. Once surgery
Box 1 Summary statement and recommendations The following recommendations have been developed by the DDH Task Force of the AAP Section on Orthopedics: 1. Tight swaddling of the lower extremities with the hips extended should be avoided. The concept of safe swaddling, which does not restrict hip motion, minimizes the risk for DDH. 2. The AAP, the Pediatric Orthopaedic Society of North America, the American Academy of Orthopaedic Surgeons, and the Canadian DDH Task Force recommend newborn and periodic screening examinations for DDH to include evaluating for positive Ortolani maneuver in newborns and young infants, detection of limb-length discrepancy, asymmetric thigh or buttock (gluteal) creases, limited abduction (generally positive after 3 months of age) and associated findings of torticollis, ligamentous laxity, and foot deformity. 3. Evidence strongly supports screening for and treatment of hip subluxation and dislocation (Ortolani positive) and observation of milder early forms of dysplasia and instability (Barlow positive). 4. It is acceptable to refer children with suspected DDH or with positive risk factors to a pediatric orthopedist without a prior ultrasound, which is preferable to obtaining an improperly timed or poorly performed study. 5. Treatment of neonatal DDH is not an emergency. In-hospital initiation of bracing by the primary care physician or other health professional is not required if infants with persistent instability are referred to the orthopedic surgeon within several weeks. Initiation of treatment is based on the clinical examination of instability. 6. Ultrasonography can be useful between 4 weeks and 4 to 6 months of age for infants with risk factors for DDH. These risk factors include clinical instability, breech presentation, and positive family history. Other considerations for imaging studies, especially if there is a persistent concern about the clinical examination include first-born girls, parental concern, and a history of improperly performed lower extremity swaddling. 7. Radiography (AP and frog lateral pelvis views) is useful after 4 to 6 months of age for infants with risk factors or positive clinical findings. There is a period between 4 and 6 months of age when either a radiograph or ultrasound imaging can be used. 8. A reasonable goal for the primary care physician should be to prevent hip subluxation or dislocation by 6 months of age using the periodic examination. Selective ultrasonography or radiography is used in consultation with the pediatric radiologist and orthopedist. Screening programs have not completely eliminated the risk of a late presentation of DDH. Milder forms of dysplasia may resolve spontaneously or with early treatment. However, dysplasia that may require arthroplasty in young adults has not been completely prevented by screening and early treatment.
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has failed and revision is contemplated, this repeat surgery in older children has very poor overall long-term results (Box 1). SUPPLEMENTARY DATA
Supplementary data related to this article can be found online at http://dx.doi.org/10. 1016/j.pcl.2014.08.008. REFERENCES
1. Bache CE, Clegg J, Herron M. Risk factors for developmental dysplasia of the hip: ultrasonographic findings in the neonatal period. J Pediatr Orthop B 2002; 11(3):212–8. 2. Imrie M, Scott V, Stearns P, et al. Is ultrasound screening for DDH in babies born breech sufficient? J Child Orthop 2010;4(1):3–8. 3. Yamamuro T, Ishida K. Recent advances in the prevention, early diagnosis, and treatment of congenital dislocation of the hip in Japan. Clin Orthop Relat Res 1984;184:34–40. 4. Rosendahl K, Markestad T, Lie RT. Ultrasound screening for developmental dysplasia of the hip in the neonate: the effect on treatment rate and prevalence of late cases. Pediatrics 1994;94:47–52. 5. US Preventive Services Task Force. Screening for developmental dysplasia of the hip: recommendation statement. Pediatrics 2006;117:898–902. 6. Salter RB. Etiology, pathogenesis and possible prevention of congenital dislocation of the hip. Can Med Assoc J 1968;98:933–45. 7. Barlow TG. Early diagnosis and treatment of congenital dislocation of the hip. J Bone Joint Surg Br 1962;44B:292–301. 8. Oniankitan O, Kakpovi K, Flanyo E, et al. Risk factors for hip osteoarthritis in Lome, Togo. Med Trop (Mars) 2009;69(1):59–60. 9. Engesaeter IO, Lie SA, Lehmann TG, et al. Neonatal hip instability and risk of total hip replacement in young adulthood: follow-up of 2,218,596 newborns from the Medical Birth Registry of Norway in the Norwegian Arthroplasty Register. Acta Orthop 2008;79(3):321–6. 10. Committee on Quality Improvement, Subcommittee on Developmental Dysplasia of the Hip. American Academy of Pediatrics: clinical practice guideline: early detection of developmental dysplasia of the hip. Pediatrics 2000;105:896–905. 11. Lipton GE, Guille JT, Altiok H, et al. A reappraisal of the Ortolani examination in children with developmental dysplasia of the hip. J Pediatr Orthop 2007;27(1):27–31. 12. Bond CD, Hennrikus WL, DellaMaggiore ED. Prospective evaluation of newborn soft-tissue hip “clicks” with ultrasound. J Pediatr Orthop 1997;17(2):199–201. 13. Scoles PV, Boyd A, Jones PK. Radiographic parameters of the normal infant hip. J Pediatr Orthop 1987;7(6):656–63. 14. Mladenov K, Dora C, Wicart P, et al. Natural history of hips with borderline acetabular index and acetabular dysplasia in infants. J Pediatr Orthop 2002;22(5): 607–12. 15. Karmazyn BK, Gunderman RB, Coley BD, et al. American College of Radiology ACR Appropriateness Criteria on developmental dysplasia of the hip—child. J Am Coll Radiol 2009;6(8):551–7. 16. Schwend RM, Schoenecker P, Richards BS, et al. Pediatric Orthopaedic Society of North America Screening the newborn for developmental dysplasia of the hip: now what do we do? J Pediatr Orthop 2007;27:607–10.
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